Glyphosate, also known as N-(phosphonomethyl)glycine is commonly used as a broad spectrum post-emergent herbicide. The herbicide is applied to the foliage of an undesired plant, whereupon it is absorbed by the foliar tissue and transported throughout the plant. Once glyphosate is absorbed in the plant, it inhibits amino acid synthesis in a biochemical pathway that is common to almost all plants, but is absent in animals.
Various salts of glyphosate, methods for preparing salts of glyphosate, formulations of glyphosate or its salts, and methods of use of glyphosate or its salts are disclosed in U.S. Pat. No. 5,998,332 to Sato et al.; U.S. Pat. No. 5,468,718 to Burval et al.; U.S. Pat. No. 4,405,531 to Franz; and “Glyphosate: A Unique Global Herbicide,” ACS Monograph 189, p. 27-64 (1997); all of which are incorporated herein in their entireties for all purposes.
The acid form of glyphosate has a low solubility in water; thereby making application of the compound difficult. As such, commercial compositions of glyphosate generally contain glyphosate salts, whereby the glyphosate acid is neutralized with a base to form the salt, which is more water-soluble than the glyphosate acid. Moreover, different salts of glyphosate have various water solubility and biological effectiveness characteristics so that there is always a need for new glyphosate salt compounds, compositions and methods of use.